Model selector

FlowModelSelector is the compact model picker made for the composer’s trailing slot: a menu of FlowModelOptions with descriptions, an optional Effort section, and an overflow behind a More models row. Picking a model or an effort applies immediately and closes the menu — no confirm step.

The picker

Models, efforts, and the overflow

FlowModelSelector(
  tooltip: 'Choose model',
  models: [
    FlowModelOption(
      id: 'fable-5',
      label: 'Fable 5',
      description: 'Our flagship model',
    ),
    FlowModelOption(
      id: 'opus-5-1',
      label: 'Opus 5.1',
      description: 'For complex & thinking tasks',
    ),
    FlowModelOption(
      id: 'haiku-4-5',
      label: 'Haiku 4.5',
      description: 'Fastest for quick answers',
    ),
  ],
  selectedId: selectedModelId,
  onSelected: (id) => setModel(id),
  // Optional: an Effort section. Picking a model or an effort
  // applies immediately and closes the menu.
  efforts: [
    FlowEffortOption(
      id: 'low',
      label: 'Low',
      description: 'Quickest replies. Simple answers',
    ),
    FlowEffortOption(
      id: 'max',
      label: 'Max',
      description: 'Complex, extensive tasks',
    ),
  ],
  selectedEffortId: selectedEffortId,
  onEffortSelected: (id) => setEffort(id),
  // Optional: overflow models behind a 'More models' row.
  moreModels: [
    FlowModelOption(id: 'sonnet-4-5', label: 'Sonnet 4.5'),
  ],
  // Presentation is automatic: an anchored menu on desktop, a
  // bottom sheet on iOS and Android. FlowMenuPresentation.menu /
  // .sheet force either.
  sheetTitle: 'Select model',
)

Presentation follows the platform

On desktop the selector anchors a menu at the trigger; on iOS and Android it presents a bottom sheet titled with sheetTitle. That’s the auto default — FlowMenuPresentation.menu or .sheet force either. Effort and More models become pushed pages inside the sheet. The sheet rides the Material modal route, so a host not built on MaterialApp needs DefaultMaterialLocalizations.delegate among its localizationsDelegates.

Key API

• models / selectedId / onSelected — the primary list; FlowModelOption carries id, label, description, and enabled.
• efforts / selectedEffortId / onEffortSelected — the optional Effort section (FlowEffortOption, same shape). When efforts is non-empty, the other two are required — a debug assert fires otherwise.
• moreModels — overflow options behind More models.
• sheetTitle, tooltip — host-supplied strings.
• effortLabel and moreModelsLabel — the widget’s two pieces of shipped copy ('Effort', 'More models'), shown on those rows and as their sheet-page titles; override both to localize.
• presentation — FlowMenuPresentation.auto (default) / .menu / .sheet.
• menuStyle — a FlowMenuStyle for per-instance retheming; enabled: false mutes the trigger.